Magento 2: How to additonalClasses for Tab in form ui component?

Question

i try this code but it not working with tab in form ui component:

<item name="additionalClasses" xsi:type="array">
 <item name="my-custom-class" xsi:type="boolean">true</item>
</item>

• Rutvee Sojitra: what you want to exactly?
• NewBie: i want add class to my custom tab in form ui component?
• Rutvee Sojitra: Do you want to additionClass for form filed or left side custom tab?
• NewBie: left side custom tab

Answer 1

Try this code to add additonalclasses for tab in form ui component.

More information in details, Visit, How to additonalClasses for Tab in Magento 2 UI component form

<fieldset name="address" sortOrder="30">
 <settings>
 <additionalClasses>
 <class name="custom-address">true</class>
 </additionalClasses>
 </settings>
</fieldset>

Hope this helps. Thanks.

Answer 2

Try using following example:

<?xml version="1.0" encoding="UTF-8"?>
<form xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Ui:etc/ui_configuration.xsd">
 <fieldset name="websites" sortOrder="30">
 <argument name="data" xsi:type="array">
 <item name="config" xsi:type="array">
 <item name="additionalClasses" xsi:type="string">admin__field-medium</item>
 </item>
 </argument>
 </fieldset>
</form>

• NewBie: It does not working with Magento 2.3 :(
• Sohel Rana: This is tested code in 2.3 :) Makesure you use this correctly
• NewBie: I tried it but nothing happened
• Rutvee Sojitra: Your answer is right @SohelRana but it's for form filed... it want for custom left tab
• NewBie: yes, I apologize for not clarifying